Nip former, fixing device, and image forming apparatus

Abstract

A nip former that forms a nip between an endless belt and a pressure rotator includes a base that is made of aluminum and has a nip forming face disposed opposite the nip. An anodic oxidation coating is treated with sealing and coats at least the nip forming face. The anodic oxidation coating has a thickness that is not smaller than 22 μm and is not greater than 45 μm and a variation in thickness that is not greater than 20 percent. The base and the anodic oxidation coating define a nip forming portion that is disposed opposite the nip. The nip forming portion has a thickness that is not smaller than 0.40 mm and is not greater than 1.20 mm.

The invention claimed is: 
     
       1. A nip former for forming a nip between an endless belt and a pressure rotator, the nip former comprising:
 a base being made of aluminum and having a nip forming face disposed opposite the nip; and 
 an anodic oxidation coating treated with sealing and configured to coat at least the nip forming face, the anodic oxidation coating having a thickness being not smaller than 22 μm and not greater than 45 μm and a variation in thickness being not greater than 20 percent, 
 the base and the anodic oxidation coating defining a nip forming portion disposed opposite the nip, the nip forming portion having a thickness being not smaller than 0.40 mm and not greater than 1.20 mm. 
 
     
     
       2. The nip former according to  claim 1 ,
 wherein the base further has an outboard face disposed outboard from the nip forming face, and 
 wherein the anodic oxidation coating treated with sealing is configured to coat the outboard face. 
 
     
     
       3. A fixing device comprising:
 an endless belt formed into a loop; 
 a pressure rotator disposed outside the loop formed by the endless belt and disposed opposite the endless belt; 
 a heater configured to heat the endless belt; and 
 a nip former disposed within the loop formed by the endless belt, the nip former configured to form a fixing nip between the endless belt and the pressure rotator, 
 the nip former including:
 a base being made of aluminum and having a fixing nip forming face disposed opposite the fixing nip; and 
 an anodic oxidation coating treated with sealing and configured to coat at least the fixing nip forming face, the anodic oxidation coating having a thickness being not smaller than 22 μm and not greater than 45 μm and a variation in thickness being not greater than 20 percent, 
 the base and the anodic oxidation coating defining a fixing nip forming portion disposed opposite the fixing nip, the fixing nip forming portion having a thickness being not smaller than 0.40 mm and not greater than 1.20 mm. 
 
 
     
     
       4. The fixing device according to  claim 3 ,
 wherein the endless belt has an inner face disposed opposite the nip former, and 
 wherein a lubricant is applied between the nip former and the inner face of the endless belt. 
 
     
     
       5. The fixing device according to  claim 3 ,
 wherein the nip former includes a plate. 
 
     
     
       6. The fixing device according to  claim 3 ,
 wherein the pressure rotator includes a roller. 
 
     
     
       7. An image forming apparatus comprising:
 an image forming device configured to form an image; and 
 a fixing device configured to fix the image on a recording medium, 
 the fixing device comprising:
 an endless belt formed into a loop; 
 a pressure rotator disposed outside the loop formed by the endless belt and disposed opposite the endless belt; 
 a heater configured to heat the endless belt; and 
 a nip former disposed within the loop formed by the endless belt, the nip former configured to form a fixing nip between the endless belt and the pressure rotator, 
 the nip former including:
 a base being made of aluminum and having a fixing nip forming face disposed opposite the fixing nip; and 
 an anodic oxidation coating treated with sealing and configured to coat at least the fixing nip forming face, the anodic oxidation coating having a thickness being not smaller than 22 μm and not greater than 45 μm and a variation in thickness being not greater than 20 percent, 
 the base and the anodic oxidation coating defining a fixing nip forming portion disposed opposite the fixing nip, the fixing nip forming portion having a thickness being not smaller than 0.40 mm and not greater than 1.20 mm.